Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel mouse model for autism yields clues to a 50-year-old mystery

21.03.2012
Early disruptions in serotonin signaling in the brain may contribute to autism spectrum disorder (ASD), and other "enduring effects on behavior," Vanderbilt University researchers report.

Serotonin is a brain chemical that carries signals across the synapse, or gap between nerve cells. The supply of serotonin is regulated by the serotonin transporter (SERT). In 2005, a team of Vanderbilt researchers led by Randy Blakely and James Sutcliffe identified rare genetic variations in children with ASD that disrupt SERT function.

In a new study published this week in the Proceedings of the National Academy of Sciences (PNAS), the researchers report the creation of a mouse model that expressed the most common of these variations.

The change is a very small one in biochemical terms, yet it appears to cause SERT in the brain to go into "overdrive" and restrict the availability of serotonin at synapses.

"The SERT protein in the brain of our mice appears to exhibit the exaggerated function and lack of regulation we saw using cell models," said Blakely, director of the Vanderbilt Silvio O. Conte Center for Neuroscience Research.

"Remarkably, these mice show changes in social behavior and communication from early life that may parallel aspects of ASD," noted first author Jeremy Veenstra-VanderWeele, assistant professor of Psychiatry, Pediatrics and Pharmacology.

The researchers conclude that a lack of serotonin during development may lead to long-standing changes in the way the brain is "wired."

In 1961, investigators at Yale discovered that as many as 30 percent of children with autism have elevated blood levels of serotonin, a finding described as "hyperserotonemia."

Since then, these findings have been replicated many times. Indeed, hyperserotonemia is the most consistently reported biochemical finding in autism, and is a highly inherited trait. Yet, the cause or significance of this "bio-marker" has remained shrouded in mystery.

Until now. In the current study, Veenstra-VanderWeele, Blakely and their colleagues showed that they could produce hyperserotonemia in mice that express a variant of a human SERT gene associated with autism.

Because the genetic change makes the transporter more active, higher levels of serotonin accumulate in platelets and therefore in the bloodstream. In the brain, overactive transporters should have the opposite effect – lowering serotonin levels at the synapse and producing behavioral changes relevant to autism. That's exactly what the researchers observed.

Of course, no mouse model can completely explain or reproduce the human condition. Neither does a single genetic variation cause autism. Experts believe the wide spectrum of autistic behaviors represents a complex web of interactions between many genes and environmental factors.

But animal models are critical to exploring more deeply the basis for the developmental changes that are observed in ASD. The scientists are using these mice to explore how altered brain serotonin levels during development may produce long-lasting changes in behavior and impact the risk for autism.

Scientists from the National Institute of Mental Health, the Medical University of South Carolina and the University of Texas Health Science Center in San Antonio contributed to the study.

The research was supported by the National Institutes of Health, the advocacy organization Autism Speaks and the American Academy of Child and Adolescent Psychiatry.

Bill Snyder | EurekAlert!
Further information:
http://www.vanderbilt.edu

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>